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Old Nov 18, 2012, 10:02 PM
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Joined Jul 2008
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Pusher-Puller Delta

Hi guys!

Just had to share,I hope it's ok!

Recently destroyed my stock stryker(hitting a sign post full bore) and crashed my other little homemade speedy wing (overpowering experiment melted jst connector..)
So I was itching for speed and built this delta.

28" wingspan
2- himax 2015s (unknown Kv)
2- Castle phoenix 25s
1- Venom 1300mah 20C battery
Graupner 3"-3" cam props direct drive.
Flying weight 13.8 oz (10.3 without battery)

Wattmeter test showed 235W on ONE motor-prop static!

Flat ( rectangle cross section) CF stock along LE.
CF tube across top and bottom


Bottom:


Quarter rear view:


Wingtip:


Wires and speedcontrollers burried in the foam to cut frontal area.
(There are air inlets at the LE and vents past the Speed controllers for cooling.)


Poor man's motor mount. Ugly but it worked so far.

Yes thats hot glue,and it did not melt with throttle management.

Maidened like a dream. Gave it about 1/3 throttle, aimed it between two trees due to lack of flying field,(Woods and a deserted paved road is all I had) gave it a frisbee toss and it tracked solid with plenty of power.

This thing is a freaking beast! I could not believe the power to weight ratio it has.

After feeling it out a little I did a speed pass where I noticed a slight climb when throttle is nailed. Some downthrust will be needed for the rear motor.( I guess)

Then I noticed that on the first two speed passes I did not even give it all the throttle it had so on the next line up I opened her up and just about browned my pants.
I will say it will do 100+MPH but no way for me to tell. I was very tempted to strap my garmin GPS on top of it to see max speed but decided it was a bad idea.

Rolls are axial in both directions and I did not even try for that. I could not believe it. (all homemade eyeballed crap,insulation,tape,balsa control horns soaked in CA, scrap pieces of hardware etc.)

Glide in for landing is very similar feel to a stock Stryker C.
Put her down on the side of the road in the grass. Motors,battery,ESC barely warm!

Anyhow just had to vent the excitement!
Thanks for checking it out!

(I can't see the embedded pictures so I uploaded attachments)
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Old Nov 19, 2012, 06:33 AM
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The_RattleSnake's Avatar
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Post a video and someone can doppler it for the top speed.
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Old Nov 19, 2012, 07:30 PM
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Quote:
Originally Posted by The_RattleSnake View Post
Post a video and someone can doppler it for the top speed.
I will do that as soon as I get a chance to make a video.

What is the best way to do it for doppler? Straight flyby as close as possible and maybe stay in throttle for a few seconds after passing by the camera?

Or some other way?

Thanks!
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Old Nov 19, 2012, 09:05 PM
I'm overcoming gravity!
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USA, NC, Huntersville
Joined Jul 2008
3,826 Posts
Do you have a smart phone? If so, just download the "RC Speedo" app. Put your phone on the ground in the middle of your flight path and fly over it. It will doppler your speed with each pass and even announce it verbally.
To get an accurate doppler reading, you need to make sure to keep the throttle steady and fly level over your phone and continue your speed run for a good ways past your phone before chopping the throttle. I usually do 8 or 10 speed passes and then look at the results. If 5 or 6 of those passes show 108 to 112mph, then I figure I have a 110mph plane.
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Old Nov 21, 2012, 05:21 AM
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Thanks Murman!

I don't have a smart phone. My wife does but she is really connected to it...

However I managed a video of a few passes. Not a real flying field for sure.

I hope there are useful passes in there for a reading or two.

If someone could doppler it for me I would appreciate it!

RC delta speed passes for doppler (2 min 35 sec)
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Old Nov 21, 2012, 05:53 AM
Wake up, feel pulse, be happy!
C₄H₁₀'s Avatar
United States, AK, Fairbanks
Joined Aug 2009
12,389 Posts
Try to make your passes as straight and level as possible; the climbing and diving will skew the Doppler results as well as the actual speed. It's also best to leave the throttle in one position for about three seconds coming in and three more going out. It looks like you might need to find a more open flying space to make any of that happen
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Old Nov 21, 2012, 11:30 PM
Near-Earth object
United States, NC, Castle Hayne
Joined Sep 2012
176 Posts
Still learning how to use RC Speedo, but it says your passes were from the low eighties up to the low nineties. Not bad.
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Old Nov 22, 2012, 08:29 AM
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Originally Posted by bluecnc View Post
Still learning how to use RC Speedo, but it says your passes were from the low eighties up to the low nineties. Not bad.
Thank you!

I got my co-worker to download the app on his phone and we got the same readings. 95 MPH being the highest.

I will redesign the battery compartment on top and the "fin" on the bottom to more aerodynamic/less frontal area and try again.

Flying in confined spaces makes the plane feel soo much faster than it actually is.
I could swear it is faster than my Diamond Dust wich was radar clocked at 115 MPH before.

Thanks again!
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